public HttpResponseInfo Copy()
{
HttpResponseInfo copy = (HttpResponseInfo)this.MemberwiseClone();
return(copy);
}
/// <summary>
/// A powerful function that performs, via HttpClient, an HTTP GET request,
/// but while adding the following helpful functions:
/// 1) If <paramref name="settings"/> (<see cref="HttpNotModifiedProperties"/>) is not null,
/// it allows a conditional GET request to be made.
/// 2) Timeout allows a true timeout to be set that doesn't have to use the deeply flawed
/// HttpClient timeout value. This is a great design flaw since their design requires the HttpClient
/// to be reused globally.
/// 3) Useful information is returned about the request, the HttpStatus, the basic result (Success or NotModified
/// or Failed...), and the HttpHeaders, as well as NotModified related information that can be used on the next
/// request to make a 304 (NotModified) request (<see cref="HttpResponseInfo"/> inherits <see cref="HttpNotModifiedProperties"/>).
/// 4) Timing diagnostics on the response times, for both headers and content.
/// 5) Exceptions are caught, but set on the <see cref="HttpResponseInfo.Ex"/> property.
/// </summary>
/// <param name="url">Url to GET.</param>
/// <param name="settings">Not modified properties in order to make a not-modified request.</param>
/// <param name="timeout">Timeout if any.</param>
/// <param name="client">Client if any.</param>
/// <param name="cancellationToken">Cancellation token.</param>
public static async Task <HttpResponseInfo> GetAsync(
string url,
HttpNotModifiedProperties settings = null,
TimeSpan?timeout = null,
HttpClient client = null,
CancellationToken?cancellationToken = null)
{
var swTotal = Stopwatch.StartNew();
if (url.IsNulle())
{
throw new ArgumentNullException(nameof(url));
}
var s = settings ?? new HttpNotModifiedProperties();
HttpResponseInfo h = new HttpResponseInfo()
{
Date = DateTimeOffset.UtcNow
};
h.CopyValuesToThis(s);
if (client == null)
{
client = _getHttpClient();
}
CancellationToken cancelToken = cancellationToken ?? new CancellationToken();
bool condGet = s.ConditionalGet;
TimeSpan _timeout = timeout ?? TimeSpan.Zero;
if (_timeout <= TimeSpan.Zero)
{
_timeout = DefaultTimeout;
}
//if(timeoutSeconds > 0) // problem, HttpClient is supposed to be used globally!!
// client.Timeout = TimeSpan.FromSeconds((int)timeoutSeconds);
bool closeClient = client == null;
try {
// --- PREP REQUEST ---
var request = new HttpRequestMessage(HttpMethod.Get, url)
.SetDefaultHeaders();
// set request IfModifiedSince header if available
if (condGet)
{
request.Headers.IfModifiedSince = s.LastModified;
}
// set request ETag if available
if (condGet && s.ETag.NotNulle())
{
//request.Headers.IfNoneMatch.Add(new EntityTagHeaderValue(""))
request.Headers.Add("If-None-Match", FixETag(s.ETag));
}
// -- GET RESPONSE --
try {
var sw = Stopwatch.StartNew();
var response = await client
.SendAsync(request, cancelToken)
//.SendAsync(request, HttpCompletionOption.ResponseHeadersRead, cancelToken)
.TimeoutAfterAsync(_timeout);
h.HeaderResponseTime = sw.ElapsedAndReset();
TimeSpan remainingTime = _timeout - h.HeaderResponseTime;
if (remainingTime <= TimeSpan.Zero)
{
remainingTime = TimeSpan.FromMilliseconds(1);
// shouldn't happen, but if TimeoutAfterAsync didn't throw, make this not
// a negative number at least, which is invalid for the next TimeoutAfterAsync call
}
h.StatusCode = response.StatusCode;
h.ResultHeadersDict = response.GetHeadersDictionary();
h.ResultHeaders = h.ResultHeadersDict.__kvHeadersToString();
// --- Status code checks ---
if (response.StatusCode == HttpStatusCode.NotModified)
{
h.Result = HttpResponseResult.NotModified;
return(h);
}
bool isSuccess = response.IsSuccessStatusCode;
h.Result = isSuccess
? HttpResponseResult.Success
: HttpResponseResult.Fail;
// OLD! now we DO allow content to be read even if is fail,
// only NotMod stops the content from being read
//if (!response.IsSuccessStatusCode) {
// h.Result = HttpResponseResult.Fail;
// return h;
//}
if (isSuccess)
{
// --- ETag ---
string responseEtag = FixETag(h.ResultHeadersDict.V("ETag")); // response.Headers.ETag; // IS NULL!! STUPID!! Come on guys!
if (condGet && s.ETag.NotNulle() && responseEtag == s.ETag)
{
h.Result = HttpResponseResult.NotModified;
return(h);
}
h.ETag = responseEtag;
// --- ContentLength check #1) If Content-Length header is set ---
int?contentLengthHeader = h.ResultHeadersDict.V("Content-Length").TrimIfNeeded().ToIntN();
if (condGet && s.ContentLengthNotModified(contentLengthHeader))
{
// contentLengthNotModified(eqCntLenNotMod, contentLengthHeader, s.ContentLength)) {
h.Result = HttpResponseResult.NotModified;
return(h);
}
}
// --- READ CONTENT ---
sw.Start();
byte[] data = await response.Content
.ReadAsByteArrayAsync()
.TimeoutAfterAsync(remainingTime);
h.ContentResponseTime = sw.ElapsedAndStop();
if (data == null)
{
data = new byte[0]; // this seems right
}
h.ContentData = data;
int dataLen = data.LengthN();
// --- ContentLength check #2) If actual data length is equal ---
if (isSuccess && condGet && s.ContentLengthNotModified(dataLen))
{
h.Result = HttpResponseResult.NotModified;
return(h);
}
h.ContentLength = dataLen; // methods above should have set, but no hurt
return(h);
}
catch (Exception ex) {
h.Result = HttpResponseResult.Fail;
if (ex is TimeoutException)
{
h.Result = HttpResponseResult.TimeOut;
}
else
{
h.Ex = ex; // don't save if just a timeout
}
return(h);
}
}
finally {
if (closeClient && client != null)
{
client.Dispose();
}
if (h != null && swTotal != null && swTotal.IsRunning)
{
h.TotalResponseTime = swTotal.Elapsed;
}
}
}